Register now to get rid of these ads!

hemi head question

Discussion in 'The Hokey Ass Message Board' started by silent rick, Jan 31, 2008.

  1. silent rick
    Joined: Nov 7, 2002
    Posts: 4,586

    silent rick
    Member

    i have truck heads on my 354 chrysler.as you all know, truck heads are like early 331 heads. the coolant exits the intake surface through the manifold unlike the later chryslers that have a crossover out the front of the heads.
    i'm running a weiand supercharger intake that has no provision to take coolant from the heads. my plan is to drill and tap the front of the heads for 1/2 inch pipe thread. i would then thread in a close nipple and onto it, a homemade flange from 3/8 inch thick stock that i could attach a stock coolant crossover between the heads. does this sound like it will work?
    has anybody here drilled into the front of the head? i know it's been done. i was wondering on the thickness, whether it is thick enough to be able to thread it with a pipe tap, screw in the nipple and have enough thread contact to seal.
    short of trading for later car heads, is there a better way?
     
  2. Bass
    Joined: Jul 9, 2001
    Posts: 3,351

    Bass
    Member
    from Dallas, TX

    Drill and tap the heads. There's enough material there to tap, but it's not very thick before you get to the water jacket. I'd say thickness is in the 3/16" range....which is enough to tap for a pipe fitting.

    In the past, this was apparently a pretty common mod for Fuel and Gas cars running 331's or the early /truck/ Industrial heads with blowers. And it will be much easier than trying to go through the intake, since you are running a blower.
     
  3. silent rick
    Joined: Nov 7, 2002
    Posts: 4,586

    silent rick
    Member

    thanks brian, my main concern was whether there was enough thickness to get a couple threads tapped. i saw a set of mondello prepped truck heads on ebay once that had about an inch of pipe coming from the front of the heads. making flanges for the stock water crossover to bolt to was an idea i had.
     
  4. silent rick
    Joined: Nov 7, 2002
    Posts: 4,586

    silent rick
    Member

    the truck heads already have hardened exhaust seats. i'm getting all new stainless valves. don't think it will be worth it to up the intakes from 1.94 to 2.00 inch, not with the supercharger forcing air through them. the exhaust are 1.75
    i wasn't planning on much boost. maybe 5 lbs to start until i familiarize myself with reading plugs and tuning, then go to 7, maybe 8 tops.
     

  5. QQMOON
    Joined: Oct 7, 2002
    Posts: 1,309

    QQMOON
    Member

    Rick try and use a fitting with a 5/8 hole as it will slow the water enough and run a hose from each head up to the top tank of the radiator works great for me and does not overheat at all
     
  6. silent rick
    Joined: Nov 7, 2002
    Posts: 4,586

    silent rick
    Member

    so two hoses like a flathead? one off each head directly to the radiator, no thermostat? isn't 1/2 inch pipe i.d. 1/2 inch. what about stepping up to 3/4 inch pipe?
     
  7. silent rick
    Joined: Nov 7, 2002
    Posts: 4,586

    silent rick
    Member

    got to examining the heads a little better today. i stated up above that the heads had 1.94 intake valves. i assumed they were 1.94 because it's a 354.
    2.00 inch intake valves didn't appear until 1957 with the introduction of the 392. well i was pleasantly surprised. i have 2.00 inch intakes. then it dawned on me, this 354 came from a 58 dodge pickup. so i guess even though it's a 354, it got the 392 size valves. i'm liking these truck heads more and more every day.
     
  8. Gotgas
    Joined: Jul 22, 2004
    Posts: 7,035

    Gotgas
    Member
    from DFW USA

    Does it use the big sodium-filled exhaust valves? They used them on most Industrials and some trucks. Some guys avoid them since their big stems reduce flow. But who cares! It's a Hemi. :D

    My '57 Chrysler still has its 392 and just got a '55 331 from an Imperial today. :cool: Good day for me and you both. :)
     
  9. FEDSLED
    Joined: Jan 4, 2003
    Posts: 251

    FEDSLED
    Member
    from lynnweed

    Anybody have any pics of this mod??? sounds like a easy cure..
     
  10. silent rick
    Joined: Nov 7, 2002
    Posts: 4,586

    silent rick
    Member

    yes, the exhaust valves are the thick sodium filled ones. but i'm replacing both intakes and exhaust valves with stainless.
    also, the exhaust valves had rotators on them which required a shorter spring, which limited lift before they went into spring bind. all that will be changed.
    learn more about these engines everyday.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.